Gravitational Correction to Running of Gauge Couplings

TL;DR

This paper calculates how graviton exchange affects the evolution of gauge couplings, showing it shifts the unification scale and makes all couplings asymptotically free, without disrupting unification.

Contribution

It provides the first perturbative calculation of gravitational effects on gauge coupling running and demonstrates their impact on unification and asymptotic freedom.

Findings

Gravitational corrections shift the gauge coupling unification scale.

These corrections render gauge couplings asymptotically free.

Unification remains intact despite gravitational effects.

Abstract

We calculate the contribution of graviton exchange to the running of gauge couplings at lowest non-trivial order in perturbation theory. Including this contribution in a theory that features coupling constant unification does not upset this unification, but rather shifts the unification scale. When extrapolated formally, the gravitational correction renders all gauge couplings asymptotically free.